<?php
/**
 * Created by PhpStorm.
 * User: Weizehua
 * Date: 8/6/2016
 * Time: 15:27
 */
$cur = floor(time()/10);
$hash = md5(strval($cur));
if(isset($_REQUEST['flag']))
{
    $flag = $_REQUEST['flag'];
    if($flag == $hash)
    {
        $f = fopen("succeed.txt", "w+");
        fwrite($f, strval(time()) . '\n');
        fclose($f);
    }
}